The Medicine Branch is a major clinical facility of the National Cancer Institute. Its activities include clinical trials in cancer patients and clinical research efforts aimed at understanding the natural history of disease, interaction of drugs used for treatment, effects of therapy on the host and tumor, and techniques for earlier diagnosis. Due to merger of Medical Breast Service into the Medicine Branch, responsibilities now encompass all areas of adult medical oncology on the NIH reservation. Clinical studies are conducted by the 7.5 senior staff. Clinical resources include 26 beds and 4 outpatient afternoon clinics per week. The total outpatient census approaches 700 patients and the majority of all therapy is administered in the outpatient clinics. The Medicine Branch has made an increasing commitment to a greater variety of common solid tumors. Clinical investigations include staging of non-Hodgkin's lymphomas, peritoneoscopy, study of reproductive capacity and second tumors after chemotherapy, and an oncology chemotherapy nurse program.